#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <assert.h>
char* my_strcat(char* dest, const char* src)
{
	assert(dest && src);
	char* ret = dest;
	while (*dest != '\0')
		dest++;
	while (*dest++ = *src++)
		;
	return ret;
}
int main()
{
	char arr1[20] = "hello";
	char arr2[] = "world";

	my_strcat(arr1, arr2);
	printf("%s\n",arr1);
	return 0;
}